1. Field of the Invention
This invention relates to a common electrodynamic transducer, also referred to as an electro-acoustic converter, such as a speaker or microphone. The invention further relates to an improved magnetic circuit used in the electrodynamic transducer.
2. Discussion of the Background
The most popular design of transducers used today in electrodynamic loudspeakers has a moving coil in a magnetic field as the moving mechanism. This mechanism has three primary parts: the voice coil, the permanent magnet, and the flux return structure which can be a center pole piece. The relation between the magnetizing force and magnetic flux density in the common electrodynamic transducer is non-linear. Therefore, when magnetic flux of a voice coil passes through a center pole, the magnetic reaction in the voice coil can result in a distorted output signal from the electrodynamic transducer.